now that the Dropbox plugin seems to work fine, we have enabled sync to Dropbox for our main development share. We have around 150 GB data and sync this to a 1 TB Dropbox Pro account. We also use the snapshot feature of the BTRFS filesystem, and the incremental snapshots are stored in a subfolder ("Synced Folder"/snapshots), taking up very little space as it should using BTRFS. On the Dropbox backup however, it seems the dropbox app copies the linked files in the snapshot folder as complete files, for each snapshot adding 150GB of data - and now our dropbox is full. An easy fix would be to use exlude list or selective sync to avoid syncing the snapshots folder, since that is completely redundant - but this is not possible to set in the interface. Is there any way of excluding the snapshots folder from syncing?
(Another option could be to configure snapshots to store the data outside of the parent folder when initially setting up the snapshots system. Unfortunately, this location cannot be changed afterhand, and creating a new folder with correct settings will confuse our users - would be best to avoid this solution)
it seems the dropbox app copies the linked files in the snapshot folder as complete files
To clarify this: There are no "linked files" in the snapshot. As far as BTRFS goes, the snapshots contain regular files that happen to share datablocks with the main share and other snapshots. So if they are visible in the share, they will be synced, and they will increase the space.
A simple workaround is to uncheck "allow snapshot access" in the share settings.
A variant is to switch to custom snapshots, setting a reasonable retention period. Then
set "only take snapshots with changes"
clear "allow snapshot access"
set "allow access to windows previous versions"
Snapshots aren't thinned like "smart" snapshots, but they are only taken when things change, which often has a similar benefit. Personally I like having a retention limit, I don't like the fact that some "smart" snapshots persist forever.
The suggested settings don't allow direct access to the snapshot folder, but (from windows) you can still right-click on folder or a file, and see the previous versions in the snapshots that you can restore.
I believe that will also prevent dropbox from syncing them.
I believe you are correct, restricting access to the snapshots folder will prevent dropbox from syncing. However, we are currently relying on access to the snapshots for users to retrive earlier versions of files, retraining them to use windows built in previous versions is not ideal. If that is the only way around this issue we might have to, however - it is important for us (regulatory reasons) to have access to unlimited versioning back to the file creation date, in addition to the other layers of backup we have on and off site. If I understand your second variant correctly, we would have to use a limited retention period, which is not ideal. I will investigate tomorrow whether any of these solutions will work for us.
If I understand your second variant correctly, we would have to use a limited retention period, which is not ideal.
The months setting will take values up to 828 months (69 years), if you try to go higher it will misbehave. Seems to me that should be high enough for any practical purpose..
BTW, you are losing some versions with the "SMART" snapshots due to the thinning.
